1. Field of the Invention
A key signature actuator for a musical keyboard eases playing from music written with a difficult key signature by automatically actuating the sharps or flats in the key signature.
2. Description of the Prior Ar
The musical keyboard is structured so as to facilitate performance of music in the major diatonic key of C. As early as the fifteenth century, keyboard instruments have had a row of front digitals to play the diatonic scale and a row of back digitals to play other tones of the chromatic scale. The major mode of the diatonic scale is started with the C tone, played on a C front digital. The succeeding D, E, F, G, A, B tones are played on the succeeding D, E, F, G, A, B front digitals.
The traditional way of writing music, used as early as the eleventh century, is to position symbols on a staff consisting of horizontal lines. The seven tones of the diatonic scale are now represented by notes on the lines and in the spaces of five-line staffs. Interspersed tones of the chromatic scale are referred to the basic notes of the diatonic scale by means of sharp or flat symbols which serve as corrections to the basic diatonic notes. Thus, a chromatic tone intermediate to the C and D tone is represented by C.music-sharp. or D.music-flat..
For a diatonic musical composition to be written without the use of sharp or flat symbols, it must be written in the key of C. Such a restriction would severely limit the choice of a modern composer, for he probably wants to base his composition on a tonic above or below the C tone. This would be no problem for singers or for musical instruments having uniform pitch changers; but many musical instruments do not have uniform pitch changers. So composers and their publishers resort to a rather unsatisfactory method for specifying the absolute pitch of their diatonic scale--they start the major mode of their diatonic scale on some other note than C. This method requires that one or more of the seven diatonic notes be corrected by means of a sharp or flat symbol. The composer finds it convenient to specify these diatonic note corrections by means of a key signature that is placed at the front of each line of written music. Key signatures greatly reduce the effort needed to write modern music and to understand the written music.
In the case of a keyboard player, these diatonic note corrections require playing of the back digitals. This detracts from the former virtue of the traditional keyboard, of providing wide front digitals for the most commonly used tones. And having learned to play a musical composition written in one key, a keyboard musician finds that playing the composition written in a different key requires quite different fingering. Furthermore, the ordinary keyboard player has difficulty remembering and playing all the sharps or flats called for in the fourteen key signatures of the written music.
To alleviate these difficulties, a keyboard instrument can be provided with a device to physically actuate the tone corrections specified in the key signature. Such a device, which I call a key signature actuator, was disclosed by Martin Philipps in 1886 (U.S. Pat. Nos. 354,733 and 519,071). If, for example, the device was set for a key signature with one sharp, then the F front digital would play not the F tone but the F.music-sharp. tone instead, as called out in the key signature. This century-old key signature actuator has not been widely used because of its mechanical complexity and expense. Indeed no key signature actuators appear to be commercially available.
Uniform pitch changers, which are widely available commercially, are generally used to change the pitch of the keyboard output away from the pitch of written music, perhaps to accommodate a particular singer or group of singers. However, for two seldom-used key signatures calling for seven sharps and seven flats (keys of C-sharp and C-flat) the musical composition can be played in the key of C and a uniform pitch changer can be used to change the pitch of the keyboard output to the pitch of the written music. This simple device does not work for the other twelve key signatures of written music, however, because in order to play a diatonic scale on the front digitals it would be necessary to associate a sequence of seven notes in written music with a sequence of seven digitals of the keyboard which is shifted from the sequence of seven digitals normally associated with the seven notes.
It would of course be possible rewrite all music in the key of C for the benefit of keyboard players possessing uniform pitch changes, but such rewritten music would not be satisfactory for playing on other instruments or on other keyboards not having uniform pitch changers. Thus a device to ease playing from music written with difficult key signatures (without rewriting the music) is badly needed.
Electrical versions of a key signature actuator are described in my U.S. Pat. Nos. 3,986,422 and 4,048,893. The second of these inventions is unable to actuate key signatures having six or seven flats or sharps, and the keyboard fingering of accidentals is quite different for different key signatures.
U.S. Pat. No. 3,986,422 and my co-pending U.S. patent application Ser. No. 736,701 describe key signature actuators that do not have these disadvantages, but they require two extra back digitals per octave span. All of these key signature actuators operate by altering the interdigital musical intervals of the tones played by a fixed set of front digitals.
A key signature actuator greatly reduces the mechanical difficulty of playing from music written in other keys than C, because the most frequently used tones are again played on the wide front digitals of the keyboard. The mental difficulty of reading from written music is also reduced, because the musician need not constantly remember the sharps or flats called out in its key signature. Unfortunately, key signature actuators are not generally available to the suffering inexpert keyboard player.
Traditionally, the front digitals are identified by their position with respect to the groups of two or three back digitals, which serve as landmarks. Beginning keyboard students are taught to recognize the letter label for each note of written music, and to find its corresponding front digital on the keyboard using the grouping of the back digitals as landmarks.
A more direct association between the written notes and the digitals of the keyboard would be achieved by a marking on the front digitals which corresponds to the staff lines of the written music. Unfortunately, keyboards with such marking are not generally available to potential keyboard musicians.
A uniform musical keyboard having alternating front and back digitals was described in 1708 by Conrad Hanfling in Germany. Such a keyboard needs a different set of landmarks to guide the player, since the traditional grouping of two and three back digitals is absent. My U.S. Pat. Nos. 3,141,371 and 3,986,422 described landmarks which map lines of the treble and bass staffs onto this uniform keyboard. Music teachers have been reluctant to teach music on the uniform keyboard, partly because they themselves have become so dependent on the landmarks formed by the irregular grouping of the back digitals.
Many musicians and inventors have proposed other keyboard structures and music notations. In spite of their considerable benefits, the difficulties of changing over to a new system have prevented most improvements from being generally adopted.